Even Moderate Amount of Pesticide Exposure Linked to Low Birth Size

A study being reported in the journal, Pediatrics, has found that among nearly 500 newborns whose umbilical cord blood was tested for pesticide residues, those with higher levels tended to be smaller at birth.

The findings are based on 494 infants born in Valencia, Spain between 2003 and 2006. Researchers found that for each 10-fold increase in any of the four pesticides in newborns’ cord blood, birth weight dipped by roughly 2 to 4 ounces.

The chemicals in question include DDT and three other organochlorines—an older group of pesticides that are now banned or restricted in the U.S. and other developed countries, after research linked them to cancer and other potential health risks. The problem, however, is that most of these pesticides persist in the environment for years, so exposure is likely through diet, particularly when consuming dairy products and oily fish.

The study also found that higher levels of DDT were linked to a decrease in head circumference, while another pesticide—hexachlorobenzene (HCB), once used as a fungicide—was tied to a shorter birth length.